1. Field of the Invention
This invention relates to mounting and clamping devices, specifically to a clamping device comprising unitary construction wherein two rail plates are connected via a bridge to one another in back-to-back orientation, and are also connected via an extension of that same bridge to an inverted U-shaped clamping member having a vertically-extending slot and opposed interior ridges on both sides of the slot. The present invention clamping device can be used to rapidly and securely mount a float switch from the top edge of a fluid collection container wall (metal or plastic), and further impart stability to the mounted float switch that will allow the float switch to reliably and repeatedly monitor fluid level changes within the container for extended periods of time with little or no maintenance or inspection, and also allow the float switch to promptly take action to stop fluid flow into the container any time the depth of fluid already accumulated therein exceeds a pre-determined threshold level considered safe. The present invention clamping device further requires no hole in the container wall for its mounting, thus saving labor/expense over the installation prior art devices used for float switch installation that require a hole to be drilled on-site in a container wall or otherwise formed in the wall in advance of installation. Furthermore, only two fasteners are typically needed to securely fix the wide inverted U-shaped clamping member into its position of use over the top edge of a vertically-extending container wall, with this simple mounting procedure saving additional installation time over that needed for prior art devices, with the additional time savings in part being a consequence of the rapid mounting procedure used and in part due to the rail plate connection of the float switch housing that automatically places the float body associated with the housing in the level orientation needed for its optimal function, with the only after-mounting action required by an installer being confirmation that float body deployment occurs at or before the pre-determined threshold depth of fluid accumulation in the associated pan no longer considered safe and if it doesn't, adjustment of the float body to the proper height. This height adjustment can easily be accomplished by release of the lock-nut securing the rail plate connection member of a float switch housing within one of the rail plate channels of the present invention, subsequent raising or lowering of the rail plate connection member within the channel, and then a re-tightening of the lock-nut to securely fix the rail plate connection member again within the rail plate's open-front configuration channel. Also, the sturdy and substantial construction of the clamping member, the secure and non-wobbling engagement of the clamping member with the container wall, and the secure and non-wobbling connection of the float switch housing to one of the present invention rail plates, all help to significantly reduce the opportunity for a change in float switch orientation over time that could diminish float switch responsiveness or function. Additionally, preferred plastic materials make the clamping device impervious to corrosion and reliable for extended duration use. No other clamping device is known with the same dual rail plate and bridge structure, or known to provide all of the advantages of the present invention.
2. Description of the Related Art
When air conditioning condensate and other fluids are collected, there is often a risk of overflow or back-up into the system producing it, even when a large pan or other large container is employed to collect the generated fluid, or a drain line connection is added. As a result, liquid-level monitoring float switches have been used with fluid collection pans for automated shut-off of the source of condensate or other fluid flow when the amount of fluid collected within it exceeds a pre-determined threshold depth considered safe. Furthermore, particularly in condensate collection applications, the condensate generally continues to flow into a collection container for a period of time (at least several minutes) after the system or unit producing it has been turned off. Therefore, prompt shut-off of fluid/condensate production is always desired when safety concerns are realized. Thus, float switches are usually made and installed to react in a very minimal depth of collected fluid, unless a specific application dictates otherwise. However, there is a common practice among installers that further complicates low-level fluid collection monitoring. They often tilt a fluid collection pan or other fluid collecting container toward one of its corners to prevent central accumulation of fluid that could add significant weight to a pan, particularly a suspended fluid collection pan, thereby substantially accelerating the probability of its deformation, cracking, and/or collapse. While the pan tilting practiced by installers solves one important problem, it creates another, how to best monitor fluid in the corner of a pan with minimal delay of shut-off signal generation. Pivoting float switch bodies have more reliable operation than those whose deployment is guided only by a centrally positioned rod, and are preferred. However, known prior art float switch mounting devices typically secure pivotally-deployed float switches so that they extend outwardly from a collection pan wall in an orientation perpendicular to the supporting wall, with the deployable end of the float body located at the greatest distance from the pan wall. This distance might be as much as three inches, or greater. Therefore, even if a float switch mount is moved as close as it can possibly get to a corner of a fluid collection pan, the deployable end of the float switch still remains a minimum of approximately three inches away from that corner and is not able to monitor the area of a tilted pan where the greatest fluid accumulation is expected to occur. In contrast, the present invention mounting device (with its dual rail plates located in a back-to-back orientation one to the other) causes the deployable end (also referred to herein as a test lever) of a float body to extend outwardly from one of the rail plates in a direction substantially parallel to the container wall. Thus, when the clamping member of the present invention is placed over the top edge of a fluid collecting container wall to position the deployable end (test lever) of a float body as close as it can get to a collection pan corner (and still remain freely deployable and responsive to rising fluid depth), the lateral portion of the deployable end becomes located no more than one-half inch from the pan's corner and in a very good position to monitor corner fluid accumulation, as well as cause a prompt fluid shut-off signal to be sent to the fluid-producing system responsible for fluid accumulation in the container when fluid depth in the corner exceeds a pre-determined depth no longer considered safe. Thus, the total amount of fluid collected prior to shut-off signal generation is significantly diminished, reducing the overall risk of injury and damage to the fluid-producing system and/or container surroundings. In addition, the back-to-back orientation of the present invention rail plates to one another also provides an installer with another advantage over prior art float switch mounting devices, the option of placing the float switch to the right of the clamping member, or to the left, whichever best suits an application.
Furthermore, the design and construction of present invention overcomes lean in problems that sometimes result from the use of condensate collection pans having insubstantial construction which may occur as a result of a small/thin wall thickness dimension, a wall with inconsistent thickness dimension, and/or materials that do not hold up well in the high temperatures often experienced in attics where some pan installations occur. Therefore, when a float switch is mounted on a pan wall, the mere addition of its weight to the wall may cause the wall to lean in and adversely change the switch's vertical orientation, and as the orientation becomes changed, the switch's responsiveness to rising fluid levels may become diminished or sporadic, thus negating its primary purpose of reliable and long-term fluid monitoring, as well as prompt shut-off of fluid production when a threshold depth of fluid accumulated in the pan considered safe is exceeded. Also, when the installation of prior art float switches requires the drilling of at least one hole through the wall of a fluid collection pan or other fluid collecting container, the time and cost of installation is increased. In contrast, the present invention uses at least two fasteners (preferably two, but more is an option) to securely fix a clamping member over the top edge of the wall of a fluid collection pan, and no pre-made hole or on-site drilling in the wall is required for clamping member installation, significantly reducing installation time and expense. Furthermore, a plurality of present invention features (including but not limited to vertically-extending interior ribs, a tubular bridge between back-to-back rail plates and a clamping member, and an inverted U-shaped clamping member having sturdy construction) all contribute to strengthening the present invention clamping device and allowing it to have a stable installation even on weaker fluid collection pan walls, as well as overcome the lean in problems and resulting orientation change for mounted float bodies that would be otherwise be expected to occur and diminish or otherwise adversely affect float body responsiveness to rising fluid as it accumulates in an associated fluid collection pan. No prior art mounting device is known to have dual rail plates in a back-to-back orientation to one another that extends a float switch in a direction parallel to the container wall supporting it (instead of providing a perpendicular extension) so that a small amount of fluid in the corner of a tilted container can be used for prompt/reliable fluid level monitoring and shut-off. In addition, no other structure is known that provides all of the benefits and advantages of the present invention clamping device.